Auto-Vacuum in 8.1 was ineffective for me. 8.2 may work better?

When I upgraded a busy database system to PostgreSQL 8.1, I was excited
about AutoVacuum, and promptly enabled it, and turned off the daily
vacuum process.

(
I set the following, as well as the option to enable auto vacuuming
stats_start_collector = true
stats_row_level = true
)

I could see in the logs that related activity was happening, but within
a few days, the performance became horrible, and enabling the regular
vacuum fixed it.

Eventually autovacuum was completely disabled.

What could have happened? Is 8.2 more likely to "just work" in the
regard? Is the the table-specific tuning that I would have needed to do?

I realize getting autovacuuming to work could be one way to exclude the
large table I wrote about in a recent post.

   Mark